Starting in the 1920s and through the 60s, almost every broadcast engineer was a licensed amateur radio operator.  That has changed a bit, but the importance of being a ham has not.  Both venues involve getting an RF signal from point A to point B.  But it is interesting to note that radio broadcast and amateur radio are similar and yet so different.  For those who don’t know much about ham radio, I’ll tell you that communicating locally or internationally, via licensed amateur radio, can be a fascinating and challenging hobby.  There are about 700,000 hams in the U.S. and an equal number worldwide. 

Physics
Broadcast and amateur radio operate with the same laws of science.  Transmitters, transmission lines, antennas and receivers make up an RF path to convey a message.  Broadcast engineers know that signal propagation on AM and FM bands is dramatically different.  It is because our FM band is roughly 100 times the frequency and 1/100^th the RF wavelength of that on the AM band.  Engineers also know that 950 MHz STL signals are line-of-sight and roughly a ten times jump in frequency from FM broadcast frequencies.  Each band has its own challenges in getting a useable signal through.

Amateur radio operators have about 30 bands of frequencies with opportunities to explore from below the AM broadcast band up through GHz and to light.  Hams are not limited to amplitude or frequency modulation, but often use single sideband and many modes of digital.  A few communicate via teletype and/or transmit television images to friends.  Yes, some hams still use Morse Code to send and receive messages in their hobby.  Code proficiency is no longer required for getting an amateur radio license, but it is a fun personal challenge to many.   

Similarities
What I find valuable is applying what I know about amateur radio in my work as a broadcast engineer.  And, of course, it works both ways.  Forward power, reflected power, transmission line loss, antenna gain, transmitter power amplifier efficiency, and path loss are all dictated by the same rules.  The mysteries and science of RF propagation to a new broadcast engineer are a fact of life for radio amateurs. 

Hams deal with the wave propagation challenge every day.  Communicating across the world via radio waves may be lost on the Internet/Millennial Generation, but it can be a real challenge for those who want more out of life.  International contacts are common during peaks in the eleven-year solar cycle.  With 400 watts I was able to make contact with a station in Antarctica from home using a good antenna.  I made contacts to Europe, Japan, Russia and even Australia with just 100 watts from my car, mostly on 20 meters (about 14 MHz).  Talk about distracted driving!  Australia is halfway around the world from Minnesota.  The RF path between us was only open for a half hour.  It is always a thrill to be on the right frequency at the right time.

As with broadcast, profanity is not allowed on amateur radio.  Don’t confuse amateur radio with Citizens Band.  CB is a sad story about people transmitting on the 27 MHz band using bad language and unacceptable social conduct.  Hams can lose their licenses for that.

Differences
Broadcasters are licensed for specific frequencies at specific power levels.  Hams might run up to 1500 watts of RF peak power in most bands of frequencies.  Good operating practice is to transmit with only the amount of power necessary to reach the other end.   Some delight in the challenge of contacting amateur stations world-wide with a watt or less of power.

Broadcasters modulate AM, FM, and/or digital as per their license.  FCC rules mandate tightly controlled occupied bandwidths.  Hams select one of many modulation types, although the bands are divided into segments for each modulation type, just to keep order.  Broadcast transmitters are required to maintain a tight frequency tolerance.  Hams can wander up and down authorized frequency bands looking for a clear spot to call CQ (calling anyone listening who might want to talk.)  They can and do easily converse with hams in foreign countries.  That is far more fun and challenging than just listening.

Hams don’t “broadcast” to a city or the world.  They don’t play music or run program as you will find on the AM and FM broadcast bands.  Instead, amateurs communicate with other hams one on one by voice, digital or Morse Code.  Sometimes hams participate in “nets” where groups meet on frequency to share ideas.  The net control operator turns the frequency over to one at a time for the rest of the group to hear.

In broadcasting, almost anyone can buy a station, a construction permit, or a license.  It just takes money.   Amateur radio is different.  For a fee of about $35.00, a person can write an exam to prove his or her knowledge of electronics and FCC rules.  With a passing grade, the FCC will issue a license to that person, good for ten years with a cost of only $35 to renew.  Try that in broadcasting!

Amateur Radio currently has three levels of licensing: Technician, General, and Extra.  Climbing that ladder with examinations gets hams more privileges and operating frequencies.  Many thousands have done it and so can you, especially now that proficiency with Morse Code is no longer required.

Mark Persons, WŘMH, is a Life Member of the Society of Broadcast Engineers, and one of only 10 people to receive its John H. Battison Award for Lifetime Achievement.